No Feign Client for loadBalancing defined.Did you forget to include spring-cloud-starter-loadbalance

使用openfeign进行远程调用,出现下面错误

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'memberController': Unsatisfied dependency expressed through field 'couponFeignService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.jane.shop.member.feign.CouponFeignService': Unexpected exception during bean creation; nested exception is java.lang.IllegalStateException: No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalancer?
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:660) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1413) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:917) ~[spring-context-5.3.4.jar:5.3.4]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:582) ~[spring-context-5.3.4.jar:5.3.4]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.3.jar:2.4.3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:767) [spring-boot-2.4.3.jar:2.4.3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.4.3.jar:2.4.3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426) [spring-boot-2.4.3.jar:2.4.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:326) [spring-boot-2.4.3.jar:2.4.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1311) [spring-boot-2.4.3.jar:2.4.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1300) [spring-boot-2.4.3.jar:2.4.3]
	at com.jane.shop.member.MemberApplication.main(MemberApplication.java:23) [classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.jane.shop.member.feign.CouponFeignService': Unexpected exception during bean creation; nested exception is java.lang.IllegalStateException: No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalancer?
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:537) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:657) ~[spring-beans-5.3.4.jar:5.3.4]
	... 21 common frames omitted
Caused by: java.lang.IllegalStateException: No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalancer?
	at org.springframework.cloud.openfeign.FeignClientFactoryBean.loadBalance(FeignClientFactoryBean.java:316) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
	at org.springframework.cloud.openfeign.FeignClientFactoryBean.getTarget(FeignClientFactoryBean.java:343) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
	at org.springframework.cloud.openfeign.FeignClientFactoryBean.getObject(FeignClientFactoryBean.java:322) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
	at org.springframework.cloud.openfeign.FeignClientsRegistrar.lambda$registerFeignClient$0(FeignClientsRegistrar.java:224) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.obtainFromSupplier(AbstractAutowireCapableBeanFactory.java:1231) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1173) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564) ~[spring-beans-5.3.4.jar:5.3.4]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.4.jar:5.3.4]
	... 29 common frames omitted

问题：
由于SpringCloud Feign在Hoxton.M2 RELEASED版本之后不再使用Ribbon而是使用spring-cloud-loadbalancer，所以不引入spring-cloud-loadbalancer会报错
解决方法：
加入spring-cloud-loadbalancer依赖 并且在nacos中排除ribbon依赖，不然loadbalancer无效。

<dependency>
	<groupId>com.alibaba.cloudgroupId>
	<artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
	<exclusions>
		<exclusion>
			<groupId>org.springframework.cloudgroupId>
			<artifactId>spring-cloud-starter-netflix-ribbonartifactId>
		exclusion>
	exclusions>
dependency>
<dependency>
	<groupId>org.springframework.cloudgroupId>
	<artifactId>spring-cloud-starter-loadbalancerartifactId>
	<version>2.2.1.RELEASEversion>
dependency>